The Baptist minister-turned-politician won some 60 percent to McCain's 24 percent and captured all 36 of the delegates at stake in Kansas on Saturday. Texas Rep. Ron Paul had 11 percent.
"It sends a pretty significant signal to John McCain that he's got a lot of work to do to get significant factions of the Republican Party solidly behind him," said Kris Kobach, the state Republican Party chairman.
McCain was denied the party nomination in 2000 when he lost to George W. Bush. Seen as the front-runner early in the campaign, McCain struggled last summer, short on cash and losing staff. He rebounded with wins in New Hampshire, South Carolina and Florida, and the bigger prizes on Super Tuesday. He all but sealed the nomination on Thursday when chief rival Mitt Romney bowed out.
McCain has a solid lead in the delegate race with 719 to Huckabee's 234. A total of 1,191 delegates is needed to secure the GOP nomination.
Huckabee addressed the conference early on Saturday and secured the win in Kansas later in the day. Speaking to reporters after his victory, he said Texas Gov. Rick Perry, a McCain supporter, called him after Super Tuesday and asked him to drop out.
"Had he been my endorser, I would have taken that quite seriously," Huckabee said. "But since he was endorsing my opponent, the recommendation rang a little hollow to me. I've yet to have one supporter, one donor, one endorser, approach me and suggest that I need to get out of the race."
Instead, "our fundraising is off the charts for us - is at record levels - and more than ever, people are gravitating toward us."
Huckabee scoffed at the idea that he should quit. He said Republican leaders "ought to be begging me to stay in" because competition toughens the party and without him Republicans will get no attention in the presidential race as long as Obama and Clinton are fighting it out.
"It's an awfully weak party that can't handle competition," he said. "Competition breeds excellence."
Huckabee likened himself to Ronald Reagan when Reagan challenged an incumbent for the 1976 nomination. "He was the pariah of the party," he said. "Now people love Ronald Reagan."
Huckabee reminded conservative activists at the conference that half the states still haven't voted.
"There are only a few states that have voted - 27 have not," Huckabee said. "People in those 27 states deserve more than a coronation, they deserve an election."
Huckabee said he is comfortable with where his campaign is now, given the resources he's had, and he plans to stay in the campaign until he can win or his opponent has the delegates to claim the prize.
"I won't drop out until at least that happens, then we'll see," he said at a news conference later. "We raised more than a quarter of a million dollars in 24 hours online yesterday."
His speech at the conservatives conference was attended by more than 1,000 people who applauded wildly at his announcement that he is staying in the race. The ballroom was about two-thirds full, however, with rows of empty seats at the fringe. Several times supporters broke out in chants of "We like Mike."
Huckabee appealed to the audience by playing up conservative themes, including references to his faith, his firm opposition to abortion and his determination to replace the Internal Revenue Service with a national sales tax.
However, the winner of a straw poll of the conference's conservatives was Romney.
Asked whether he might consider the No. 2 spot on the ticket with McCain, Huckabee said: "I'm not at all. I don't have any illusion that Senator McCain would select me as a running mate, or that I would automatically select him."